Abstract: Monthly mean 100hPa geopotential heights for five months(APR. - AUG. ) from 1956 through 1984 in the area 10-40°N, 60- 130 °E)are analized by EOF method. Four eigenvectors selected acording to their contributions to total covariance repre sent respectively the major characters of Southern Asia High(SAH), i. e. mean strength, south-north oscilatiori, east-west oscilation and ridge-line tilt. Similar analysis is used to the rainfall anormalies for summer season in 11 subareas. Analysis on time coefficients of SAH and the rainfall show significant effects of SAH behaviour on summer rainfall in China, which is consistent with synoptic experiences. The self correlation of time coefficient and relationship between two time coefficients may offer a way to long range rainfall forecasting.